In a parallel-plate type substrate processing apparatus, plasma is generated by applying RF (radio frequency) to one of a pair of electrodes, and a substrate (Wafer) placed on the electrode to which the RF is applied or on the other electrode is processed by this plasma.
Here, an art in which a positive voltage in a pulse state is applied as a bias to suppress a charge up damage and a local abnormal etching (notching) is disclosed.
However, it turns out that it is not necessarily possible to perform an effective process even if the positive voltage in the pulse state is applied.